This invention relates to remote control stations for printing machines.
Currently printing machines such as offset printing presses are remotely controlled from a central control terminal or control desk. Control information and machine parameters are passed from the control terminal to the printing press through one or more microcomputers monitoring and adjusting printing function such as register and ink density. See, for example, Schramm et al. U.S. Pat. No. 4,200,932 issued Apr. 29, 1980, for which a reexamination certificate issued Apr. 26, 1983. Currently all of the major printing machine manufacturers sell similar remote control systems, each of which has a rather elaborate control terminal or control desk.
A typical remote control desk has indicators in the form of rows of emitting diodes, luminous switches, digital indicators or screens, and input units in the form of keyboards or selector switches. Depending on the data indicated by the rows of LEDs or the digital display, the operator activates any number of the keys on the control unit. In addition to manufacturers' literature, control units are described in patents such as West German Pat. No. 2,728,738.
If displays and input devices such as keyboards are provided for each control function, the operators are compelled to switch repeatedly between different displays and inputs. Such a control terminal also uses an excessive number of mechanical components and occupies a great deal of space.
To reduce the operator time required to switch from one set of input and display devices to another, it is known to centralize controls for the printing machine and to reduce duplication of devices as taught in West German Pat. No. 3,100,451. A central control panel includes adjustment units for the fountain roller drives and the printing register, along with a separate control unit for remote adjustment of the inking zones. But switching facilities are required for the operations to fix the operating range, and hence a large number of controls are still required.
It is also known how to use visual display units, which operate with the aid of a light pen for the control and monitoring of machines. The light pen, for example, can select various steps or branches on a flow diagram displayed, in whole or in part, on the screen of the visual display unit. A particular disadvantage of using a light pen for machine control is that the light pen includes a photoelectric cell which is susceptible to dirt and other environmental effects. Hence work places using light pens sensing video display screens should be enclosed in clean areas away from production printing machines to ensure reliable operation of the control and monitoring system. See, for example, page 634 of Druck-Print No. 10/1980, pp. 633-635, wherein video displays are used in the press room office.
Recently a substitute for the light pen has been developed consisting of a transparent, touch sensitive matrix sensor or switch which may be placed over the screen of a visual display unit. The combination of a touch sensitive matrix and visual display unit, for example, has been used as the operator interface of a Xerox 5700 copying machine. See, for example, FIG. 4, page 2326, and FIG. 5, page 2327 of SBZ/JIS, No. 40, 1981, pp. 2324-2328.
It is apparent, however, that the mere use of a video display unit with a light pen or touch-sensitive matrix does not provide access to the numerous inputs and outputs that are currently provided on the remote control terminal for a printing machine. This should be evident from the fact that a single screen cannot by itself display all of the information required by a printing machine operator to supervise and control printing operations.